Vanquish would pretty much be a guaranteed purchase for me, it was one of the first PS3 games I played soon after buying the console. Got it with the instant game collection with PS+ and really enjoyed the game, it could have been a bit lighter on QTEs for my taste but otherwise the whole Gears of War mixed with Crysis thing it had going on was fun.
Gears had gotten a bit stale for me by the time I finished 3 (I never even bought Judgement), although Vanquish pinched many of Gears core gameplay elements it was pretty fresh. It did its own thing enough to more than make Vanquish its own game, it just shared some of those familiar mechanics that made Gears so great. Plus all the giant robots, mechs and the environments along with level design where simply awesome, there where loads of great weapons and upgrades. grabbing the shells being fired from a 30m tall battle mechs cannon and ramming them back down the barrel is pretty spectacular, the Citadel from Mass Effect style space station was a welcome change from grey and brown post apocalypse cityscapes too
If I got the chance to play it on the PC with beefed up graphics but everything else intact I would even pay full price, those levels, enemies and the ARS suit would look brilliant with last gen equivalent PC quality graphics let alone this gen equivalent.
